Light flashes can come from, for example, lightning or scintillation. Scintillation is a flash of light produced by an ionization event in a material that is transparent to light. The process of scintillation is one of luminescence whereby light of a characteristic spectrum is emitted following the absorption of radiation. The emitted radiation may be less energetic than that absorbed. Scintillation is an inherent molecular property in conjugated and aromatic organic molecules and arises from the electronic structure of said molecules. Scintillation also occurs in many inorganic materials, including salts, gases, and liquids.